The refinement of rotational speed derivative correction in gas turbines

The design of the acceleration schedule is one of the core applications of gas turbine parameter correction. Due to safety and performance demands, the estimation accuracy of the correction exponent is becoming increasingly strict. This study deduces refined formulas for the correction exponents of rotational speed derivative (N-dot), as N-dot is one of the primary options for the acceleration schedule. Its estimation accuracy has improved by approximately 29% in average relative error and about 44% in relativized absolute error compared to Volponi's method. Additionally, this study also deduces refined temperature correction formulas for the burner inlet and high-pressure turbine inlet, and provides a general formula for N-dot. Moreover, this research offers a proof of the transformation formula for the correction between the original parameters and their derivatives, which was not provided in previous studies. Finally, the distribution standard deviation of the minimum surge margin obtained through the N-dot schedule control acceleration process, designed according to the formulas proposed in this study, is 0.95%, which is significantly smaller than 2.84% of Volponi's method.